GREP positive lookahead with OR condition

Hi there,

suppose I'm trying to find all the occurrences of WORD just before a paragraph end (\r) OR at story end (\z)

why is this GREP not working?

WORD(?=\r|\z)

while as single queries WORD(?=\r) and WORD(?=\z) they work?

How do I need to apply the OR?

Thanks so much!

L.